In steam injection applications for oil reservoirs, in order to increase sweep efficiency in long steam injection wells, and thereby increase oil recovery, it is desirable for the steam to be distributed “equally” along an inclined, horizontal, or vertical openhole section. However, due to reservoir heterogeneity and cumulative friction pressure drop along the openhole wellbore, the steam will generally flow unevenly along the formation, thus leading to poor sweep efficiency.
Currently, there are a number of downhole outflow control technologies that can be introduced in injection applications. For instance, outflow control tools can be used to create back-pressure between the annular space and inner space of completion strings, and thereby affect injection pressure along the wellbore (the annulus pressure) in an attempt to “equalize” the injection profile. This technology generally utilizes openhole packers, such as swellable packers, to isolate the long horizontal wellbore into multiple injection units. Swellable packers have a swellable elastomer bonded thereto that, when deployed downhole and subjected to an activating agent (such as water, oil, or both), swells on the packer and eventually engages a surrounding sidewall of the openhole. However, conventional swellable packers have been shown to provide inadequate sealing under high temperature (above 400° F.) conditions due to temperature degradation of the packing element.
Therefore, there is a need for a reliable packer suitable for use under high temperature conditions for steam injection outflow control applications.